Pharmaceutical composition including pimobendan

ABSTRACT

A solid formulation includes pimobendan or a pharmaceutically acceptable salt thereof, which is homogenously dispersed with a polyvalent acid and a flavor suitable to animals.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. Nonprovisional application Ser. No. 14/465,273, filed 21 Aug. 2014 and entitled “Pharmaceutical Composition Including Pimobendan”, which is a continuation of U.S. Nonprovisional application Ser. No. 13/802,989, filed 14 Mar. 2013 and entitled “Packaging Assembly for Pharmaceutical Composition Including Pimobendan,” which is a continuation of U.S. Nonprovisional application Ser. No. 13/402,292, filed 22 Feb. 2012 and entitled “Pharmaceutical Composition Comprising Pimobendan,” which is a divisional of U.S. Nonprovisional application Ser. No. 11/072,207, filed 4 Mar. 2005 and entitled “Pharmaceutical Composition Comprising Pimobendan,” which claims priority to German Patent Application No. 102004011512, filed on 8 Mar. 2004. The disclosure of each aforementioned application is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The invention relates to the field of animal health. In particular, the invention relates to novel oral pharmaceutical compositions comprising, as part of the pharmaceutically active compounds, pimobendan.

BACKGROUND OF THE INVENTION

Pimobendan, (4,5-dihydro-6-[2-(4-methoxyphenyl)-1H-benzimidazol-5-yl]-5-methyl-3(2H)-pyridazone) is disclosed in U.S. Pat. No. 4,361,563, herein incorporated by reference in its entirety. Pimobendan is a cardiotonic, hypotensive and anti-thrombotic. Said substance is useful in the treatment of congestive heart failure.

Pimobendan hardly dissolves in water. The resorption of pimobendan when administered orally is prone to considerable inter- and intra-individual fluctuations if the active substance is incorporated in known or conventional pharmaceutical forms for oral administration. The reason for this is that pimobendan is characterized by a low solubility in aqueous media and a very highly pH-dependent solubility. To overcome this, hard gelatine capsules were used containing pimobendan formulated with citric acid, in particular at a weight ratio of pimobendan to citric acid of between 1:10 and 1:20 (U.S. Pat. No. 5,364,646, herein incorporated by reference in its entirety). However, the high quantity of citric acid and the acidic taste of citric acid is not readily accepted by most animals—thus, such capsules have to be force-fed to the animals or mixed with food prior to application.

The problem underlying the present invention was to provide a pimobendan solid formulation readily acceptable by mammalian subjects, especially small animals.

SUMMARY OF THE INVENTION

The invention relates to novel solid formulations comprising as a pharmaceutically active compound pimobendan or a pharmaceutically acceptable salt thereof which is homogenously dispersed in a polyvalent acid and a flavor acceptable to small animals. Preferably, such solid formulations are granules or tablets. Most preferred is a tablet characterized in that the tablet comprises, 1.25 mg, 2.5 mg, 5 mg or 10 mg pimobendan, and further comprises lactose, corn starch, croscarmellose-sodium, citric acid, preferably at an amount of 50 mg/g of the solid formulation, artificial beef flavor, polyvidone, colloidal anhydrous silica and magnesium stearate.

The invention further relates to fluid-bed granulation processes for production of the solid formulations comprising the following steps:

-   -   a) an aqueous solution of pimobendan and a binder as defined         above is sprayed onto a solid carrier bed comprising one or more         carriers and/or excipients, flavor and citric acid anhydride and     -   b) the resulting mixture is dried and     -   c) the dried mixture is sieved and de-agglomerated and     -   d) a flow regulator is added to the sieved and de-agglomerated         mixture and     -   e) a lubricant is added to the resulting mixture and     -   f) the resulting mixture with lubricant is blended for         uniformity of granules to obtain final granules and/or     -   g) the final granules are compressed to solid formulations.

Step g) is omitted if the solid formulation is a granule. If the solid formulation is a tablet, step g) is carried out.

Furthermore, the invention relates to a method of prevention and/or treatment of diseases wherein cardiotonic, hypotensive and anti-thrombotic substances have a therapeutic benefit, comprising administering to a mammal in need of such treatment a therapeutically effective amount of a solid formulation prepared as described above.

Preferred is a method of prevention and/or treatment of congestive heart failure, comprising administering to a mammal in need of such treatment a therapeutically effective amount of a solid formulation according to the invention as disclosed above. Most preferably, the method comprises administering a tablet according to the invention, as defined above.

Furthermore, the invention relates to a method for manufacturing a medicament for the prevention and/or treatment of congestive heart failure, Additionally, the invention relates to a method for manufacturing a medicament for the prevention and/or treatment of congestive heart failure, characterized in that a tablet comprising 1.25 mg, 2.5 mg, 5 mg or 10 mg pimobendan and further comprising lactose, corn starch, croscarmellose-sodium, 50 mg/g citric acid, artificial beef flavor, polyvidone, colloidal anhydrous silica and magnesium stearate is made.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1: Illustration of the basic top spray fluid bed process. Reference signs: 1 Exhaust air ventilator; 2 Filter; 3 Pump; 4 Stirrer; 5 Aqueous Suspension of micronized pimobendan and binder solution (PVP, HPMC, starch, gelatin); 6 Heating device for inlet air; 7 Sieve; 8 Nozzle, aqueous suspension is sprayed onto powder bed (citric acid, lactose, starch, flavor); 9 Powder bed.

FIG. 2: Flow Chart of Manufacturing Process.

FIG. 3: Dissolution Profiles, Pimobendan 1.25 mg tablets, showing 95% confidence intervals of the mean; USP apparatus 2 (Paddle), Rotation Speed 75 rpm, Buffer pH 4.0. Comparison of dissolution profiles of tablets which were stored 1 and 6 months at 40° C./75% in HDPE bottles; batch no. PB020049.

FIG. 4: Dissolution Profiles, Pimobendan 1.25 mg tablets, showing 95% confidence intervals of the mean; USP apparatus 2 (Paddle), Rotation Speed 75 rpm, Buffer pH 4.0. Comparison of dissolution profiles of tablets which were stored 12 days at 25° C./60% in open glass bottles; batch no. PB010080.

FIG. 5: Dissolution Profiles, Pimobendan 2.5 mg tablets, showing 95% confidence intervals of the mean; USP apparatus 2 (Paddle), Rotation Speed 75 rpm, Buffer pH 4.0. Comparison of dissolution profiles of tablets which were stored 3 and 6 months at 40.degree. C./75% in Alu-Alu Blister; batch no. PB010076

FIG. 6: Dissolution Profiles, Pimobendan 5.0 mg tablets, showing 95% confidence intervals of the mean; USP apparatus 2 (Paddle), Rotation Speed 75 rpm, Buffer pH 4.0. Comparison of dissolution profiles of tablets which were stored 6 months at 40° C./75% in HDPE bottles; batch no. PB020059.

FIG. 7: Dissolution Profiles, Pimobendan 5.0 mg tablets, showing 95% confidence intervals of the mean; USP apparatus 2 (Paddle), Rotation Speed 75 rpm, Buffer pH 4.0. Manufacturing variable: Different compression forces; batch no. PB020205.

DETAILED DESCRIPTION OF THE INVENTION

Before the embodiments of the present invention it must be noted that as used herein and in the appended claims, the singular forms “a”, “an”, and “the” include plural reference unless the context clearly dictates otherwise. Thus, for example, reference to “a tablet” includes a plurality of such tablets, reference to the “carrier” is a reference to one or more carriers and equivalents thereof known to those skilled in the art, and so forth. Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art to which this invention belongs. All given ranges and values may vary by 1 to 5% unless indicated otherwise or known otherwise by the person skilled in the art. Accordingly, the term “about” is not used in the description.

Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods, devices, and materials are described. All publications mentioned herein are incorporated herein by reference for the purpose of describing and disclosing the substances, excipients, carriers, and methodologies as reported in the publications which might be used in connection with the invention. Nothing herein is to be construed as an admission that the invention is not entitled to antedate such disclosure by virtue of prior invention.

The solution to the above technical problem is achieved by the description and the embodiments characterized in the claims.

To overcome the difficulties in the art, a process was invented. Only the invention of this novel, fluid-bed granulation process allowed the formulation of solid formulations according to the invention. With the process according to the invention, it was possible to formulate a long-term stable, capable of being produced on a large scale, homogenously dispersed, fast-releasing solid formulation. Despite the large size, pimobendan was homogenously dispersed. Such solid formulations comprise a flavor suitable for small animals, which surprisingly still allows a formulation having a polyvalent acid and yet have a palatibility rate of more than 70%—in many cases more than 90%. Thus, the solid formulations according to the invention are a major step forward in therapeutic application as they do not have to be force-fed to the animal.

In a first important embodiment, the invention relates to a solid formulation, comprising pimobendan or a pharmaceutically acceptable salt thereof, see e.g. U.S. Pat. No. 4,361,563 or U.S. Pat. No. 5,364,646 (both herein incorporated by reference in its entirety), which is homogenously dispersed in a polyvalent acid selected from the group consisting of citric acid, acetic acid, maleic acid, tartaric acid and the anhydride of any of said polyvalent acids and mixtures thereof, and a flavor acceptable to small animals. Such flavors according to the invention preferably are selected from artificial beef flavors, artificial chicken flavors, pork liver extract, artificial meat flavor, honey flavor and the like. Said flavors not only disguise the taste of the polyvalent acid, but also the taste of pimobendan.

Preferably, the solid formulation according to the invention is a tablet or granule formulation. The granule formulation according to the invention is explained in more detail below. More preferably, the solid formulation is chewable.

The invention preferably also relates to a solid formulation according to the invention, further comprising one or several pharmaceutically acceptable excipients. Excipients according to the invention are preferably selected from the group consisting of diluents, disintegrants, carriers, binders, flow regulators, lubricants and solvents. Any other excipients known to the skilled person and found suitable for the solid formulation according to the invention may also be comprised in the solid formulation according to the invention. See also Remington, J. P. The science and Practice of Pharmacy (2000). 20th ed. Lippincott Williams & Wilkins Publishers, Philadelphia, US. More preferably, said excipients are carriers/disintegrants selected from the group lactose, starch, cellulose, microcrystalline cellulose and cellulose derivatives, e.g. methylcellulose, and the like. Any other carrier known to the skilled person and found suitable for the solid formulation according to the invention may also form part of the solid formulation according to the invention. See also Remington, J. P. The science and Practice of Pharmacy (2000). 20th ed. Lippincott Williams & Wilkins Publishers, Philadelphia, US.

One or several binders according to the invention are preferably selected from the group consisting of polyvidone (used synonymously for povidone), methylcellulose, hydroxypropylmethylcellulose (HPMC), hydroxymethylcellulose, starch, gelatin, and the like. Any other binder known to the skilled person and found suitable for the solid formulation according to the invention may also be comprised in the solid formulation according to the invention. See also Remington, J. P. The science and Practice of Pharmacy (loc. cit.).

The solid formulation according to the invention may also comprise one or several flow regulators selected from the group consisting of silica, preferably colloidal anhydrous silica, calcium silicate, magnesium silicate, talc, and the like. Any other flow regulator known to the skilled person and found suitable for the solid formulation according to the invention may also be incorporated into the solid formulation according to the invention. See also Remington, J. P. The science and Practice of Pharmacy (loc. cit.).

The solid formulation according to the invention may also comprise one or several disintegrants selected from the group consisting of croscarmellose sodium, sodium starch glycolate, pregelatinised starch, cross-linked polyvinylpyrrolidone and the like. Any other disintegrant known to the skilled person and found suitable for the solid formulation according to the invention may also form part of the solid formulation according to the invention. See also Remington, J. P. The science and Practice of Pharmacy (loc. cit.).

The solid formulation according to the invention may also comprise one or several lubricants selected from the group consisting of magnesium stearate, calcium stearate, glyceryl behenate, polyethylene glycol, stearic acid, talc and the like. Any other lubricant known to the skilled person and found suitable for the solid formulation according to the invention may form part of the solid formulation according to the invention. See also Remington, J. P. The science and Practice of Pharmacy (loc. cit.).

The invention preferably also relates to a solid formulation according to the invention, characterized in that the carriers are starch and lactose. The invention preferably also relates to a solid formulation according to the invention, characterized in that the lactose consists of coarse particles greater than 200 μm in size. The person skilled in the art knows other types of lactose which are suitable as well as carrier according to the invention, e.g. fine lactose equal or smaller than 200 μm in size or spray-dried lactose. Preferred is lactose consisting of coarse particles greater than 200 μm in size.

The invention preferably also relates to a solid formulation according to the invention, characterized in that the starch or various starches are selected from the group consisting of native starch, gelatinized starch, partly gelatinized starch, starch powder, starch granules, chemically modified starch and swellable, physically modified starch.

The invention preferably also relates to a solid formulation according to the invention, characterized in that the starch is corn starch.

The invention preferably also relates to a solid formulation according to the invention, comprising 0.5 mg to 20 mg of pimobendan. The more preferred solid formulation contains 1 to 10 mg of pimobendan. The even more preferred solid formulation contains 1.25 to 5 mg of pimobendan. Most preferred solid formulations contain 1.25 mg, 2.5 mg, 5 mg or 10 mg of pimobendan.

The invention preferably also relates to a solid formulation according to the invention, comprising a content of 1:10-1:40 of pimobendan in relation to citric acid anhydride. The preferred ratio is 1:20.

The invention preferably also relates to a solid formulation according to the invention, characterized in that the weight of the whole solid formulation is in the range of 250 to 3000 mg, with a more preferred weight range of 500 mg to 2000 mg, and most preferred weight of 500 mg, 1000 mg or 2000 mg.

The invention preferably also relates to a solid formulation according to the invention, characterized in that the solid formulation is produced by a fluid-bed granulation process comprising or consisting of the steps:

-   -   a) an aqueous solution of pimobendan and a binder as defined         above is sprayed onto a solid carrier bed comprising one or         several carriers and/or excipients as defined above, flavor and         citric acid anhydride and     -   b) the mixture of a) is dried and     -   c) the mixture of b) is sieved and de-agglomerated and     -   d) a flow regulator is added to the mixture of c) and     -   e) a lubricant is added to the mixture of d) and     -   f) the mixture of e) is blended for uniformity of granules to         obtain final granules and/or     -   g) the final granules of f) are compressed to solid         formulations.

Step g) is omitted if the solid formulation is a granule. If the solid formulation is a tablet, step g) is carried out.

The invention preferably also relates to a solid formulation according to the invention, characterized in that the solid formulation is produced by a fluid-bed granulation process comprising or consisting of the steps:

-   -   a) an aqueous solution of pimobendan and povidone is sprayed         onto a solid carrier bed comprising lactose, starch, flavor and         citric acid anhydride and     -   b) the mixture of a) is dried and     -   c) the mixture of b) is sieved and de-agglomerated and     -   d) a flow regulator is added to the mixture of c) and     -   e) a lubricant is added to the mixture of d) and     -   f) the mixture of e) is blended for uniformity of granules to         obtain final granules and/or     -   g) the final granules of f) are compressed to solid         formulations.

Step g) is omitted if the solid formulation is a granule. If the solid formulation is a tablet, step g) is carried out.

The invention preferably relates to a granule formulation as obtained by the process above that can either be administered in the granular form or as tablets after compressing the final granules to tablets. Therefore, the solid formulation according to the invention preferably is a granule (or a plurality of such granules) or a tablet. The administration of the granules can take place by mixing with food or by offering the granules directly to the animal, e.g. in a bowl. The application of the granular form will allow an individual dosing of pimobendan according to the body weight of the animal.

The tablets according to the invention have surprising advantages. The dissolution profile ensures immediate release of pimobendan. Surprisingly, it could be demonstrated that while compressing the final granules as mentioned above, a decrease in the dissolution characteristics is not observed. By ensuring an immediate release profile of pimobendan, the amount of drug to be administered can be kept as low as possible, thereby improving the safety profile, which is especially important for long-term treatment.

Furthermore, the dosing accuracy of the tablet is excellent. This is due to the fact that in accordance with the manufacturing process according to this invention, an excellent uniformity of pimobendan content is achieved. Furthermore, the tablets can be broken into two halves so that half the dose per tablet can be administered. Compared with the existing gelatin capsule, the dosing accuracy and compliance of both the animal and the animal owner are assured. This is even more important since the drug is administered for a chronic condition and long-term treatment.

Also, the palatability of the tablet is excellent. More than 90% of the dogs to whom the tablet according to this invention was given accepted the tablet voluntarily with only the tablet offered in a bowl. Compared with the existing gelatin capsule, the ease of administration has increased compliance with the prescribed treatment regime. This is important since the drug is administered for a chronic condition.

The invention preferably also relates to a tablet according to the invention, characterized in that the tablet is stable for at least 18 months at 25.degree. C. and 60% relative humidity. In the examples, testing parameter assays are disclosed for degradation of pimobendan, dissolution, loss on drying, hardness and disintegration of the tablet. The tablets according to the invention are within the specification limits regarding degradation of pimobendan, dissolution, loss on drying, hardness and disintegration.

Suitable packaging materials for tablets according to the invention are selected from, but not limited to: aluminum/aluminum blisters, PVC/PVDC blisters, and HDPE (high density polyethylene bottles).

The invention preferably also relates to a tablet according to the invention, characterized in that the tablet is oblong in shape. For such a tablet, characteristics like crushing strength, disintegration, uniformity of weight and content uniformity fulfill the requirements of the European Pharmacopoeia (ISBN/ISSN 92-871-5106-7 of 4.sup.th Edition 2004, Vol. 4.8, European Directorate for the Quality of Medicines (EDQM), European Pharmacopoeia, 226 avenue de Colmar, F-67029 Strasbourg, France, http://www.pheur.org) and the United States Pharmacopoeia (http://www.usp.org; in print: USP-NF, catalog No. 2270001).

The invention preferably relates to a solid formulation, and most preferred a tablet according to the invention, characterized in that the solid formulation or tablet comprising 0.5-20 mg pimobendan, preferably of 1.25 mg, 2.5 mg, 5 mg or 10 mg pimobendan, and further comprises lactose (35-50% by weight relative to the dry mass of the solid formulation/tablet=(w/w)), corn starch (25-50% w/w), croscarmellose-sodium (1-5%), citric acid (2.5-10% w/w), artificial beef flavor (5-30% w/w), polyvidone (1-5% w/w), colloidal anhydrous silica (0.1-1, preferably 0.1-0.5% w/w) and magnesium stearate (0.25-1.5% w/w), wherein the percentage by weight of pimobendan contains preferably about 0.25% (w/w) and the sum of the percentages by weight of all ingredients of the solid formulation including pimobendan is 100% (w/w). A skilled man is in a position to prepare such solid formulations, preferably a tablet. Thus, the skilled man knows that he can add to 0.25% (w/w) pimobendan at most 32.625% (w/w) corn starch, 4% (w/w) croscarmellose-sodium 5% (w/w) citric acid, 20% (w/w) artificial beef flavor, 4% (w/w) polyvidone, colloidal, 0.5% (w/w) anhydrous silica, 1% (w/w) magnesium stearate if the amount of lactose to be 32.625% (w/w). Moreover, the skilled man also knows that if he decided to reduce the amount of the artificial beef flavor, for example, to the minimum of 5% (w/w), he can increase the amount of lactose, for example, to 47.625% (w/w). The invention also relates to a solid formulation, preferably a tablet, comprising about 0.25% (w/w) pimobendan and any of the above other ingredients of the solid formulation, preferably the tablet, in the range given above so that the sum of the amounts by weight of the individual formulation ingredients is 100%.

The present invention is also directed to a solid formulation, preferably to a tablet, which comprises 1 mg pimobendan, 100-200 mg lactose, 100-200 mg corn starch, 4-20 mg croscarmellose-sodium, 10-40 mg citric acid anhydrous, 20-120 mg artificial beef flavor, 4-20 mg polyvidone, 0.4-4 mg colloidal anhydrous silica, and 1-6 mg magnesium stearate for each 400 mg of total weight of the solid formulation, preferably a tablet. According to a further embodiment of the present invention, the solid formulation, preferably the tablet, comprises 1 mg pimobendan, 120-180 mg lactose, 120-180 mg corn starch, 8-18 mg croscarmellose-sodium, 15-30 mg citric acid anhydrous, 40-100 mg artificial beef flavor, 8-18 mg polyvidone, 0.5-2 mg colloidal anhydrous silica, and 2-5 mg magnesium stearate for each 400 mg of total weight of the solid formulation/tablet. For example, the present invention relates to a solid formulation comprising for each 400 mg of total weight: 1 mg pimobendan, 20 mg citric acid anhydrous, 130.5 mg lactose, 130.5 mg corn starch, 16 mg polyvidone, 16 mg croscarmellose-sodium, 80 mg artificial beef flavor, 4 mg magnesium stearate, and 2 mg colloidal anhydrous silica. A skilled man is in a position to prepare such solid formulation/tablet. The skilled man also knows that he can vary the amount of each ingredient of the solid formulation/tablet within the ranges given above in that the total weight of the solid formulation/tablet for each 1 mg pimobendan is 400 mg. For example, the amount of lactose may be 100, 101, 102, . . . 108, 109, 110 etc.; 111, 112, . . . 118, 119, 120 etc.; 121, 122, . . . 128, 129, 120 etc.; 131, 132, . . . 138, 139, 140 etc.; 141, 142, . . . 148, 149, 150 etc.; 151, 152, . . . 158, 159, 160 etc.; 161, 162, . . . 168, 169, 170 etc.; 171, 172, . . . 178, 179, 180 etc.; 108, 182, . . . 188, 189, 190 etc.; 191, 192, . . . 198, 199, 200 mg for each 400 mg of total weight of the solid formulation, preferably a tablet, comprising about 1 mg pimobendan. In the same manner the amount of corn starch may be 100, 101, 102, . . . 108, 109, 110 etc.; 111, 112, . . . 118, 119, 120 etc.; 121, 122, . . . 128, 129, 120 etc.; 131, 132, . . . 138, 139, 140 etc.; 141, 142, . . . 148, 149, 150 etc.; 151, 152, . . . 158, 159, 160 etc.; 161, 162, . . . 168, 169, 170 etc.; 171, 172, . . . 178, 179, 180 etc.; 108, 182, . . . 188, 189, 190 etc.; 191, 192, . . . 198, 199, 200 mg for each 400 mg of total weight of the solid formulation, preferably a tablet, comprising about 1 mg pimobendan. Furthermore, the amount of citric acid anhydrous may be 10, 11, 12, . . . 18, 19, 20 etc.; 21, 22, . . . 28, 29, 30 etc.; 31, 32, . . . 38, 39, 40 mg for each 400 mg of total weight of the solid formulation, preferably a tablet comprising about 1 mg pimobendan. Furthermore, the amount of artificial beef flavor may be 20, 21, 22, . . . 28, 29, 30 etc.; 31, 32, . . . 38, 39, 40 etc.; 41, 42, . . . 48, 49, 50 etc.; 50, 51, 52, . . . 58, 59, 60 etc.; 61, 62, . . . 68, 69, 70 etc.; 71, 72, . . . 78, 79, 80 etc., 81, 82, 83, . . . 88, 89, 90 etc.; 91, 92, . . . 98, 99, 100 etc.; 101, 102, . . . 108, 109, 110 etc.; 111, 112, . . . 118, 119, 120 mg for each 400 mg of total weight of the solid formulation, preferably a tablet, comprising about 1 mg pimobendan. Furthermore, the amount of polyyidone may be 4, 5, 6, . . . 8, 9, 10 etc.; 11, 12, . . . 18, 19, 20 mg for each 400 mg of total weight of the solid formulation, preferably a tablet, comprising about 1 mg pimobendan. Furthermore, the amount of croscarmellose-sodium may be 4, 5, 6, . . . 8, 9, 10 etc.; 11, 12, . . . 18, 19, 20 mg for each 400 mg of total weight of the solid formulation, preferably a tablet, comprising 1 mg pimobendan. Furthermore, the amount of magnesium stearate may be 1.0, 1.1, 1.2, . . . 1.8, 1.9, 2.0 etc.; 2.1, 2.2, . . . 2.8, 2.9, 3.0 etc.; 3.1, 3.2, . . . 3.8, 3.9, 40 etc.; 4.0, 4.1, 4.2, . . . 4.8, 4.9, 5.0 etc.; 5.1, 5.2, . . . 5.8, 5.9, 6.0 mg for each 400 mg of total weight of the solid formulation, preferably a tablet, comprising about 1 mg pimobendan. Furthermore, the amount of colloidal anhydrous silica may be 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 1.0, 1.1, 1.2, . . . 1.8, 1.9, 2.0 etc.; 2.1, 2.2, . . . 2.8, 2.9, 3.0 etc.; 3.1, 3.2, . . . 3.8, 3.9, 4.0 mg for each 400 mg of total weight of the solid formulation, preferably a tablet, comprising about 1 mg pimobendan. A skilled man is in a position to prepare any of such inventive solid formulation, preferably as a tablet.

In another important embodiment, the invention relates to a fluid-bed granulation process comprising the following steps:

-   -   a) an aqueous solution of pimobendan and a binder as defined         above is sprayed onto a solid carrier bed comprising one or         several carriers and/or excipients as defined above, flavor and         citric acid anhydride and     -   b) the mixture of a) is dried and     -   c) the mixture of b) is sieved and de-agglomerated and     -   d) a flow regulator is added to the mixture of c) and     -   e) a lubricant is added to the mixture of d) and     -   f) the mixture of e) is blended for uniformity of granules to         obtain final granules and/or     -   g) the final granules of f) are compressed to solid         formulations.

Step g) is omitted if the solid formulation is a granule. If the solid formulation is a tablet, step g) is carried out.

The invention preferably relates to a fluid-bed granulation process comprising the following steps:

-   -   a) an aqueous solution of pimobendan and polyvidone is sprayed         onto a solid support comprising lactose, starch, flavor and         citric acid anhydride and     -   b) the mixture of a) is dried and     -   c) the mixture of b) is sieved and de-agglomerated and     -   d) a flow regulator is added to the mixture of c) and     -   e) a lubricant is added to the mixture of d) and     -   f) the mixture of e) is blended for uniformity of granules to         obtain final granules and/or     -   g) the final granules of f) are tableted.

Step g) is omitted if the solid formulation is a granule. If the solid formulation is a tablet, step g) is carried out.

Another embodiment is a method of prevention and/or treatment of diseases wherein cardiotonic, hypotensive and anti-thrombotic substances have a therapeutic benefit, comprising administering to a mammal in need of such treatment a therapeutically effective amount of a solid formulation according to the invention as disclosed above. Preferred is a method of prevention and/or treatment of congestive heart failure, comprising administering to a mammal in need of such treatment a therapeutically effective amount of a solid formulation according to the invention as disclosed above. Most preferably, the method comprises administering a tablet according to the invention, characterized in that the tablet comprises 1.25 mg, 2.5 mg, 5 mg or 10 mg pimobendan, and further comprises lactose, corn starch, croscarmellose-sodium, citric acid preferably at an amount of 50 mg/g, artificial beef flavor, polyvidone, colloidal anhydrous silica and magnesium stearate. Preferably also, such treatment is by orally administering the solid formulation according to the invention.

The mammal according to the invention is preferably a mammal selected from the group consisting of dogs, cats and rodents such as rabbits.

Furthermore, the invention relates to a method for manufacturing a medicament for the prevention and/or treatment of congestive heart failure, characterized in that a solid formulation according to the invention is used. Preferably, the invention relates to a method for manufacturing a medicament for the prevention and/or treatment of congestive heart failure, characterized in that a tablet consisting of 1.25 mg, 2.5 mg, 5 mg or 10 mg pimobendan and further consisting of lactose, corn starch, croscarmellose-sodium, 50 mg/g citric acid, artificial beef flavor, polyvidone, colloidal anhydrous silica and magnesium stearate is used.

The present invention furthermore relates to a kit, which comprises a solid formulation, preferably a tablet according to the present invention described herein, and a package leaflet or user instruction including the information concerning how the solid formulation, preferably the tablet, is to used via the oral route for the prevention and/or treatment of congestive heart failure in a mammal in need of such prevention or treatment, preferably in a dog, cat or rodent.

EXAMPLES

The following examples serve to further illustrate the present invention; but the same should not be construed as limiting the scope of the invention disclosed herein.

Example 1 Compositions

Composition A

Composition A mg/tablet mg/tablet mg/tablet 1.25 mg 2.5 mg 5.0 mg Volatile Ingredients chewable chewable chewable ingredient kg/batch (01) Pimobendan 1.250 2.500 5.000 0.175 (02) Citric acid 25.000 50.000 100.00 3.500 anhydrous <200 μm (03) Starch 163.125 326.250 652.500 22.8375 (04) Lactose, coarse 163.125 326.250 652.500 22.8375 (05) Polyvidone 20.000 40.000 80.000 2.800 (06) Croscarmellose 20.000 40.000 80.000 2.800 Sodium (07) Artificial Powered 100.000 200.00 400.000 14.000 Beef Flavour (08) Silica, colloidal 2.500 5.00 10.000 0.350 anhydrous (09) Magnesium stearate 5.000 10.00 20.000 0.700 (10) Purified water + 500.000 1000.000 2000.000 − 70.000

Composition B

Composition B mg/tablet mg/tablet mg/tablet 1.25 mg 2.5 mg 5.0 mg Volatile Ingredients chewable chewable chewable ingredient kg/batch Pimobendan 1.250 2.500 5.000 0.175 Citric acid 25.000 50.000 100.000 3.500 anhydrous <200 μm Starch 163.125 326.250 652.500 22.8375 Lactose, coarse 238.125 476.250 952.500 22.8375 Polyvidon 20.000 40.000 80.000 2.800 Croscarmellose 20.000 40.000 80.000 2.800 Sodium Meat Flavour 25.000 50.000 100.000 14.000 Silica, colloidal 2.500 5.000 10.000 0.350 anhydrous Magnesium stearate 5.000 10.000 20.000 0.700 Purified water + 500.000 1000.000 2000.000 − 70.000

Example 2 Raw Materials

(01) Pimobendan

Function: Active ingredient

(02) Citric acid anhydrous <200 μm

Function: Diluent, Disintegrant

(03) Starch

Function: Carrier, Disintegrant

(04) Lactose coarse

Function: Carrier, Disintegrant

(05) Povidone

Function: Binder

(06) Croscarmellose Sodium

Function: Disintegrant

(07) Artificial Powdered Beef Flavor

Function: Flavor

(08) Silica, colloidal anhydrous

Function: Flow regulator, Disintegrant

(09) Magnesium stearate

Function: Lubricant

(10) Purified water

Function: Solvent

Example 3 Product Description

Appearance: brownish, oblong tablets, with break line.

Tablet Tablet Tablet Weight 500 mg 1000 mg 2000 mg Length About 19.0 mm About 24.0 mm About 25.0 mm Width About 7.0 mm About 7.5 mm About 15.0 mm Thick- About 4.2 mm About 5.6 mm About 6.0 mm ness

Example 4 Manufacturing Process

1 batch=140000 tablets (1.25 mg Dosage)

1 batch=70000 tablets (2.50 mg Dosage)

1 batch=35000 tablets (5.00 mg Dosage)

1. 1. Granulating

Transfer in a suitable Granulator after presereening: (01) Starch (e.g. 18 mesh sieve) 22.8375 kg (02) Lactose (e.g. 18 mesh sieve) 22.8375 kg (03) Citric acid anhydrous (e.g. 18 mesh sieve) 3.500 kg (04) Croscarmellose sodium (e.g. 18 mesh sieve) 2.800 kg (05) Artificial Beef Flavour (e.g. 45 mesh sieve) 14.000 kg (05) Povidone (Spray solution) 2.800 kg (06) UDCG 115 BS (Spray liquid) 0.175 kg Premix in the granulator and granulate 68.950 kg Purified water (e.g. 16.8 kg, range; 12.0-18.0 kg) is used as a solvent for the spray solution povidone and dispersion of pimobendan.

2. Screening

Screen the premixture 1. 68.950 kg 68.950 kg

3. Final Mixing

Add (07) Sillica, colloidal anhydrous (e.g. 25 mesh sieve)  0.350 kg (08) Magnesium stearate (e.g. 25 mesh sieve)  0.700 kg In a tumbling mixer, mix the screened premixture (2.) 70.000 kg and the two ingredients 70.000 kg

4. Compression

Using a rotary press, compress the final mixture (3.) 70.000 kg into tablets of 500 mg, 1000 mg, 2000 mg. 70.000 kg

5. Packaging

Transfer the tablets in a suitable container.

The tablets can be packed e.g. by blistering of the tablets in a suitable machine.

Example 5 In Process Controls

1. Granules

1.1 Appearance: Brownish, white-speckled granules

1.2 Loss on Drying: Determine the loss on drying

e.g.: HR73; 3 g/105° C./5 min

Target: approx. 3.0%

Tolerance limits: below 5.0%

2. Tablets

2.1 Appearance: Brownish, white-speckled, oblong tablets with breakline

2.2 Weight uniformity:

1) 1.25 mg chewable Average weight: 475-525 mg 2) 2.5 mg chewable Average weight: 950-1050 mg 3) 5 mg chewable Average weight: 1900-2100 mg

2.3 Hardness: Determine the hardness

1) 1.25 mg Target: 140 N Tolerance: 60-250 N 2) 2.5 mg Target: 160 N Tolerance: 60-250 N 3) 5.0 mg Target 190 N Tolerance: 60-300 N

2.4 Disintegration time: Determine the disintegration time according to USP/EP

Tolerance limits: ≦15 minutes with water at 37° C., with disks

Example 6 Palatability Study

A study to investigate the palatability of pimobendan-containing tablets was carried out. For a period of four days, two products were given to twenty or ten dogs, respectively, for voluntary uptake. For example, the following formulations with a content of 5 mg/500 mg active ingredient were examined:

Ch. 010122 (tablets with 10% Ch. 010123 (tablets with 10% content of artificial beef flavor) content of artificial beef flavor) Pimobendan 5 mg Pimobendan 5 mg (UD-CG 115 BS) (UD-CG 115 BS) Lactose 85.5 mg Lactose 55.5 mg Corn starch 199.5 mg Corn starch 129.5 mg Croscarmellose- 20 mg Croscarmellose- 20 mg Sodium Sodium Citric acid 100 mg Citric acid 100 mg Artificial Beef 50 mg Artificial Beef 150 mg Flavor Flavor Polyvidone 25 mg Polyvidone 25 mg Macrogol 6000 15 mg Macrogol 6000 15 mg Total: 500 mg Total: 500 mg

In case of Ch. 010123 in competition with the identical formulation in granulated format, a voluntary uptake was observed in 36 out of 40 possible opportunities (i.e. when offered to 10 dogs for 10 days). This compares to an acceptance rate of 90.0%.

In case of Ch. 010222 in competition with a formulation in granulated format of equal quantity with 30% flavor, a voluntary uptake was observed in 31 out of 40 possible opportunities. This compares to an acceptance rate of 77.5%.

Example 7 Dissolution Profiles

Examples for representative dissolution profiles of the tablet according to this invention are as disclosed in FIG. 3.

Dissolution Profiles, Pimobendan 1.25 mg Tablets Showing 95% Confidence Intervals of the Mean USP Apparatus 2 (Paddle), Rotation Speed 75 rpm, Buffer PH 4.0 Comparison of Dissolution Profiles of Tablets Which Were Stored 1 and 6 Months at 40° C./75% in HDPE Bottles Batch No. PB020049

Examples for representative dissolution profiles of the tablet according to this invention are as disclosed in FIG. 4.

Dissolution Profiles, Pimobendan 1.25 mg Tablets Showing 95% Confidence Intervals of the Mean USP Apparatus 2 (Paddle), Rotation Speed 75 rpm, Buffer pH 4.0 Comparison of Dissolution Profiles of Tablets Which Were Stored 12 Days at 25° C./60% in Open Glass Bottles Batch No. PB010080 Dissolution Profiles, Pimobendan 1.25 mg Tablets Manufacturing Variable: Different Compression Forces

% Dissolved, mean (n = 6) Time Tablet hardness Batch No. (min) 70 N 105 N 135 N 157 N 020102 10 82 82 81 84 20 98 97 97 98 30 101 99 100 100 45 101 101 102 102

Examples for representative dissolution profiles of the tablet according to this invention are as disclosed in FIG. 5.

Dissolution Profiles, Pimobendan 2.5 mg Tablets Showing 95% Confidence Intervals of the Mean USP Apparatus 2 (Paddle), Rotation Speed 75 rpm, Buffer pH 4.0 Comparison of Dissolution Profiles of Tablets Which Were Stored 3 and 6 Months at 40° C./175% in Alu-Alu Blister Batch No. PB010076

Examples for representative dissolution profiles of the tablet according to this invention are as disclosed in FIG. 6.

Dissolution Profiles, Pimobendan 5.0 mg Tablets Showing 95% Confidence Intervals of the Mean USP Apparatus 2 (Paddle), Rotation Speed 75 rpm, Buffer pH 4.0 Comparison of Dissolution Profiles of Tablets Which Were Stored 6 Months at 40.Degree. C./75%/ in HDPE Bottles Batch No. PB020059

Examples for representative dissolution profiles of the tablet according to this invention are as disclosed in FIG. 7.

Dissolution Profiles, Pimobendan 5.0 mg Tablets Showing 95% Confidence Intervals of the Mean USP Apparatus 2 (Paddle), Rotation Speed 75 rpm, Buffer pH 4.0 Manufacturing Variable: Different Compression Forces Batch No. 020205

% Dissolved, mean (n = 6) Tablet hardness Time Batch No. (min) 117 N 150 N 186 N 222 N 020205 10 56 56 56 56 20 76 75 76 76 30 79 79 80 80 45 80 80 81 81

Analytical Results for Pimobendan Chewable Tablet Batches Used in Stability Study % dissolved in t = 30 minutes, mean (n = 6) Tablet Initial 6 Months 6 Months 6 Months strength Batch No. Packaging value 25° C./60% 30° C./70% 40° C./75% 1.25 mg  PB020049 HDPE bottle 97 95 94 93 PB020049 Alu-Alu blister 95 93 94 PB020049 PVC/PVDC blister 94 93 93 PB020050 HDPE bottle 94 92 93 91 PB020050 Alu-Alu blister 92 92 91 PB020050 PVC/PVDC blister 93 93 92 PB020051 HDPE bottle 94 93 92 92 PB020051 Alu-Alu blister 94 93 92 PB020051 PVC/PVDC blister 93 93 91 2.5 mg PB020052 HDPE bottle 98 n.d. n.d. 93 PB020052 Alu-Alu blister n.d. n.d. 94 PB020052 PVC/PVDC blister n.d. n.d. 92 PB020053 HDPE bottle 97 n.d. n.d. 91 PB020053 Alu-Alu blister n.d. n.d. 91 PB020053 PVC/PVDC blister n.d. n.d. 91 PB020054 HDPE bottle 97 n.d. n.d. 91 PB020054 Alu-Alu blister n.d. n.d. 92 PB020054 PVC/PVDC blister n.d. n.d. 91 5.0 mg PB020059 HDPE bottle 95 93 92 92 PB020059 Alu-Alu blister 93 92 92 PB020059 PVC/PVDC blister 92 92 91 PB020060 HDPE bottle 92 91 90 89 PB020060 Alu-Alu blister 91 91 90 PB020060 PVC/PVDC blister 91 91 89 PB020061 HDPE bottle 94 91 91 89 PB020061 Alu-Alu blister 92 92 90 PB020061 PVC/PVDC blister 91 91 89 n.d. = not determined

Example 8 Content Uniformity

Samples were taken from both the final blend before tableting and from the tableting process. The following results demonstrate the uniformity of pimobendan content.

Blend Uniformity Batch Assay [mg/g] % Target 0007LP-A 2.37 94.8 0007LP-B 2.48 99.2 0007LP-C 2.43 97.2 0007LP-D 2.44 97.6 0007LP-E 2.47 98.8 0007LP-F 2.50 100.0 0007LP-G 2.49 99.6 0007LP-H 2.49 99.6 0007LP-I 2.50 100.0 0007LP-J 2.43 97.2 Average 2.46 98.4 0008LP-A 2.41 96.4 0008LP-B 2.48 99.2 0008LP-C 2.45 98.0 0008LP-D 2.45 98.0 0008LP-E 2.46 98.4 0008LP-F 2.43 97.2 0008LP-G 2.46 98.4 0008LP-H 2.44 97.6 0008LP-I 2.47 98.8 0008LP-J 2.50 100.0 Average 2.46 98.2

Uniformity of Process Batch Assay [mg/g] % Target PM020080-1 2.48 99.2 PM020080-2 2.52 100.8 PM020080-3 2.50 100.0 PM020080-4 2.52 100.8 PM020080-5 2.49 99.6 PM020080-6 2.52 100.8 Average 2.51 100.2 PM020081-1 2.45 98.0 PM020081-2 2.51 100.4 PM020081-3 2.48 99.2 PM020081-4 2.45 98.0 PM020081-5 2.47 98.8 PM020081-6 2.45 98.0 Average 2.47 98.7

Example 9 Accuracy of Broken Tablets

The tablets according to this invention were part of an content uniformity test for the broken tablets. 10 tablets were taken from the beginning, middle and end of the tabletting process and broken into two halves. The pimobendan content was determined.

Pimobendan 5 mg tablet, batch no. 0000251607 Specification Start Middle End CU min. (mg) ≧2.13 2.44 2.43 2.41 CU max. (mg) ≦2.87 2.61 2.57 2.57 CU average (mg 2.25-2.62 2.52 2.51 2.50 RSD (%) ≦6.0 2.3 1.9 2.0

Pimobendan 1.25 mg tablet, batch no. 0000251604 Specification Start Middle End CU min. (mg) ≧0.532 0.577 0.590 0.582 CU max. (mg) ≦0.718 0.664 0.650 0.645 CU average (mg 0.563-0.656 0.621 0.621 0.616 RSD (%) ≦6.0 5.4 3.4 3.6

Example 10 Stability Data After 24 Months (Dissolution/Assay of Pimobendan/Degradation of Pimobendan)

Product: Pimobendan chewable tablets 1.25 mg HDPE bottle (m) PVC/PVDC (m) Aluminium blister (m) Batch No.: PB020049 Dissolution 25° C./60° C. 0 months 95 (min)-102 0 months 95 (min)-102 0 months 95 (min)-102 (max)/97 (avg); 24 (max)/97 (avg); 24 (max)/97 (avg); 24 months 96-99/97 months 96-99/97 months 92-96/94 30° C./70° C. 0 months 95 (min)-102 0 months 95 (min)-102 0 months 95 (min)-102 (max)/97 (avg); 24 (max)/97 (avg); 24 (max)/97 (avg); 24 months 96-97/97 months 96-98/97 months 95-99/97 40° C./75° C. 0 months 95 (min)-102 0 months 95 (min)-102 0 months 95 (min)-102 (max)/97 (avg); 6 (max)/97 (avg); 6 (max)/97 (avg); 6 months 92-94/93 months 91-94/93 months 92-95/94 Batch No.: PB020049 HDPE bottle (m) PVC/PVDC (m) Aluminium blister (m) Assay of 25° C./60° C. 0 months 1.251; 24 0 months 1.251; 24 0 months 1.251; 24 Pimobendan months 1.233 months 1.236 months 1.237 30° C./70° C. 0 months 1.251; 24 0 months 1.251; 24 0 months 1.251; 24 months 1.229 months 1.242 months 1.236 40° C./75° C. 0 months 1.251; 6 0 months 1.251; 6 months 0 months 1.251; 6 months 1.221 1.214 months 1.231 Degradation of 25° C./60° C. 0 months 1) <0.10 (K2006a); 0 months 1) <0.10 (K2006a); 0 months 1) <0.10 (K2006a); Pimobendan 2) <0.10 (DU- 2) <0.10 (DU-CG 2) <0.10 (DU-CG CG 134 134 BS); 3) <0.10 (any 134 BS); 3) <0.10 (any BS); 3) <0.10 (any unspecified); 4) <0.10 (total); unspecified); 4) <0.10 (total; unspecified); 4) <0.10 (total; 24 months 1) <0.10; 24 months 1) <0.10; 24 months 2) <0.10; 3) <0.10; 4) <0.10 2) <0.10; 3) <0.10; 1) <0.10; 2) <0.10; 4) <0.10 3) <0.10; 4) <0.10 30° C./7° C. 0 months 1) <0.10 (K2006a); 0 months 1) <0.10 (K2006a); 0 months 1) <0.10 (K2006a); 2) <0.10 (DU- 2) <0.10 (DU-CG 2) <0.10 (DU-CG CG 134 134 BS); 3) <0.10 (any 134 BS); 3) <0.10 (any BS); 3) <0.10 (any unspecified); 4) <0.10 (total); unspecified); 4) <0.10 (total); unspecified); 4) <0.10 (total); 24 months 1) 0.35; 24 months 1) <0.10; 24 months 2) <0.10; 3) <0.10; 4) 0.35 2) <0.10; 3) <0.10; 1) <0.10; 2) 0.10; 4) <0.10 3) <0.10; 4) 0.10 40° C./75° C. 0 months 1) <0.10 (K2006a); 0 months 1) <0.10 (K2006a); 0 months 1) <0.10 (K2006a); 2) <0.10 (DU- 2) <0.10 (DU-CG 2) <0.10 (DU-CG CG 134 134 BS); 3) <0.10 (any 134 BS); 3) <0.10 (any BS); 3) <0.10 (any unspecified); 4) <0.10 (total); unspecified); 4) <0.10 (total); unspecified); 4) <0.10 (total); 6 months 1) 0.55; 6 months 1) <0.10; 6 months 1) 0.10; 2) <0.10; 3) <0.10; 4) 0.55 2) <0.10; 3) <0.10; 2) 0.11; 3) <0.10; 4) 0.21 4) <0.10 Batch No.: PB020050 Dissolution 25° C./60° C. 0 months 91 (min)-96 0 months 91 (min)-96 0 months 91 (min)-96 (max)/94 (avg); 24 (max)/94 (avg); 24 (max)/94 (avg); 24 months 96-104/99 months 84-101/95 months 92-96/94 30° C./70° C. 0 months 91 (min)-96 0 months 91 (min)-96 0 months 91 (min)-96 (max)/94 (avg); 24 (max)/94 (avg); 24 (max)/94 (avg); 24 months 94-102/97 months 93-102/97 months 97-105/99 40° C./75° C. 0 months 91 (min)-96 0 months 91 (min)-96 0 months 91 (min)-96 (max)/94 (avg); 6 (max)/94 (avg); 6 (max)/94 (avg); 6 months 91-92/91 months 91-93/92 months 91-92/91 Assay of 25° C./60° C. 0 months 1.231; 24 0 months 1.231; 24 0 months 1.231; 24 Pimobendan months 1.224 months 1.201 months 1.228 30° C./70° C. 0 months 1.231; 24 0 months 1.231; 24 0 months 1.231; 24 months 1.213 months 1.217 months 1.230 40° C./75° C. 0 months 1.231; 6 0 months 1.231; 6 months 0 months 1.231; 6 months 1.205 1.202 months 1.215 Degradation of 25° C./60° C. 0 months 1) <0.10 (K2006a); 0 months 1) <0.10 (K2006a); 0 months 1) <0.10 (K2006a); Pimobendan 2) <0.10 (DU- 2) <0.10 (DU-CG 2) <0.10 (DU-CG CG 134 134 BS); 3) <0.10 (any 134 BS); 3) <0.10 (any BS); 3) <0.10 (any unspecified); 4) <0.10 (total); unspecified); 4) <0.10 (total); unspecified); 4) <0.10 (total); 24 months 1) <0.10; 24 months 1) <0.10; 24 months 2) <0.10; 3) <0.10; 4) <0.10 2) <0.10; 3) <0.10; 1) <0.10; 2) <0.10; 4) <0.10 3) <0.10; 4) <0.10 30° C./7° C. 0 months 1) <0.10 (K2006a); 0 months 1) <0.10 (K2006a); 0 months 1) <0.10 (K2006a); 2) <0.10 (DU- 2) <0.10 (DU-CG 2) <0.10 (DU-CG CG 134 134 BS); 3) <0.10 (any 134 BS); 3) <0.10 (any BS); 3) <0.10 (any unspecified); 4) <0.10 (total); unspecified); 4) <0.10 (total); unspecified); 4) <0.10 (total); 24 months 1) <0.37; 24 months 1) <0.10; 24 months1) <0.10; 2) <0.10; 3) <0.10; 4) <0.37 2) <0.10; 3) <0.10; 2) <0.10; 3) <0.10; 4) <0.10 4) <0.10 40° C./75° C. 0 months 1) <0.10 (K2006a); 0 months 1) <0.10 (K2006a); 0 months 1) <0.10 (K2006a); 2) <0.10 (DU- 2) <0.10 (DU-CG 2) <0.10 (DU-CG CG 134 134 BS); 3) <0.10 (any 134 BS); 3) <0.10 (any BS); 3) <0.10 (any unspecified); 4) <0.10 (total); unspecified); 4) <0.10 (total); unspecified); 4) <0.10 (total); 6 months 1) 0.58; 6 months 1) <0.10; 6 months 1) <0.10; 2) <0.10; 3) <0.10; 4) 0.58 2) <0.10; 3) <0.10; 2) <0.10; 3) <0.10; 4) <0.10 4) <0.10 Batch No.: PB020051 Dissolution 25° C./60° C. 0 months 92 (min)-95 0 months 92 (min)-95 0 months 92 (min)-95 (max)/94 (avg); 24 (max)/94 (avg); 24 (max)/94 (avg); 24 months 92-100/96 months 94-101/97 months 91-100/95 30° C./70° C. 0 months 92 (min)-95 0 months 92 (min)-95 0 months 92 (min)-95 (max)/94 (avg); 24 (max)/94 (avg); 24 (max)/94 (avg); 24 months 92-99/96 months 95-98/97 months 92-100/97 40° C./75° C. 0 months 92 (min)-95 0 months 92 (min)-95 0 months 92 (min)-95 (max)/94 (avg); 6 (max)/94 (avg); 6 (max)/94 (avg); 6 months 91-93/92 months 90-92/91 months 91-94/92 Assay of 25° C./60° C. 0 months 1.230; 24 0 months 1.230; 24 0 months 1.230; 24 Pimobendan months 1.222 months 1.225 months 1.228 30° C./70° C. 0 months 1.230; 24 0 months 1.230; 24 0 months 1.230; 24 months 1.214 months 1.221 months 1.230 40° C./75° C. 0 months 1.230; 6 0 months 1.230; 6 months 0 months 1.230; 6 months 1.210 1.202 months 1.218 Degradation of 25° C./60° C. 0 months 1) <0.10 (K2006a); 0 months 1) <0.10 (K2006a); 0 months 1) <0.10 (K2006a); Pimobendan 2) <0.10 (DU- 2) <0.10 (DU-CG 2) <0.10 (DU-GG CG 134 134 BS); 3) <0.10 (any 134 BS); 3) <0.10 (any BS); 3) <0.10 (any unspecified); 4) <0.10 (total); unspecified); 4) <0.10 (total); unspecified); 4) <0.10 (total); 24 months 1) <0.10; 24 months 2) <0.10; 3) <0.10; 4) <0.10 1) <0.10; 2) <0.10; 3) <0.10; 4) <0.10 30° C./7° C. 0 months 1) <0.10 (K2006a); 0 months 1) <0.10 (K2006a); 0 months 1) <0.10 (K2006a); 2) <0.10 (DU- 2) <0.10 (DU-CG 2) <0.10 (DU-CG CG 134 134 BS); 3) <0.10 (any 134 BS); 3) <0.10 (any BS); 3) <0.10 (any unspecified); 4) <0.10 (total); unspecified); 4) <0.10 (total); unspecified); 4) <0.10 (total); 24 months 1) <0.33; 24 months 2) <0.10; 3) <0.10; 4) 0.33 1) <0.10; 2) <0.10; 3) <0.10; 4) <0.10 40° C./75° C. 0 months 1) <0.10 (K2006a); 0 months 1) <0.10 (K2006a); 0 months 1) <0.10 (K2006a); 2) <0.10 (DU- 2) <0.10 (DU-CG 2) <0.10 (DU-CG CG 134 134 BS); 3) <0.10 (any 134 BS); 3) <0.10 (any BS); 3) <0.10 (any unspecified); 4) <0.10 (total); unspecified); 4) <0.10 (total); unspecified); 4) <0.10 (total); 6 months 1) <0.54; 6 months 1) <0.10; 2) <0.10; 3) <0.10; 4) <0.54 2) 0.10; 3) <0.10; 4) 0.10

Product: Pimobendan chewable tablets 2.5 mg HDPE bottle (m) PVC/PVDC (m) Aluminium blister (m) Batch No.: PB020052 Dissolution 30° C./70° C. 0 months 97 (min)-99 0 months 97 (min)-99 0 months 97 (min)-99 (max)/98 (avg); 12 (max)/98 (avg); 12 (max)/98 (avg); 12 Months 93-95/94 months 93-94/94 months 94-97/96 40° C./75° C. 0 months 97 (min)-99 0 months 97 (min)-99 0 months 97 (min)-99 (max)/98 (avg); 6 (max)/98 (avg); 6 (max)/98 (avg); 6 months 93-94/93 months 91-93/92 months 93-95/94 Assay of 30° C./70° C. 0 months 2.49; 12 0 months 2.49; 12 months 0 months 2.49; 12 Pimobendan months 2.49 2.47 months 2.50 40° C./75° C. 0 months 2.49; 6 0 months 2.49; 6 months 0 months 2.49; 6 months months 2.41 2.41 2.45 Degradation of 30° C./7° C. 0 months 0 months 0 months Pimobendan 1) <0.10 (K2006a); 1) <0.10 (K2006a); 1) <0.10 (K2006a); 2) <0.10 (UDCG 134 2) <0.10 (UDCG 134 BS); 2) <0.10 (UDCG 134 BS); 3) <0.10 (any 3) <0.10 (any BS); 3) <0.10 (any unspecified); unspecified); unspecified); 4) <0.10 (total); 12 4) <0.10 (total); 12 months 4) <0.10 (total); 12 months 1) <0.10; 1) <0.10; 2) <0.10; months 1) <0.10; 2) <0.10; 3) <0.10; 3) <0.10; 4) <0.10 2) <0.10; 3) <0.10; 4) <0.10 4) <0.10 40° C./75° C. 0 months 0 months 0 months 1) <0.10 (K2006a); 1) <0.10 (K2006a); 1) <0.10 (K2006a); 2) <0.10 (UDCG 134 2) <0.10 (UDCG 134 BS); 2) <0.10 (UDCG 134 BS); 3) <0.10 (any 3) <0.10 (any BS); 3) <0.10 (any unspecified); unspecified); unspecified); 4) <0.10 (total); 6 4) <0.10 (total); 6 months 4) <0.10 (total); 6 months months 1) <0.10; 1) 0.43; 2) <0.10; 3) <0.10; 1) <0.10; 2) <0.10; 2) <0.10; 3) <0.10; 4) 0.43 3) <0.10; 4) <0.10 4) <0.10 Batch No.: PB020053 Dissolution 30° C./70° C. 0 months 96 (min)-98 0 months 96 (min)-98 0 months 96 (min)-98 (max)/97 (avg); 12 (max)/97 (avg); 12 (max)/97 (avg); 12 months 92-94/93 months 90-93/92 months 91-95/93 40° C./75° C. 0 months 96 (min)-98 0 months 96 (min)-98 0 months 96 (min)-98 (max)/97 (avg); 6 (max)/97 (avg); 6 (max)/97 (avg); 6 months 89-93/91 months 91-91/91 months 90-92/91 Assay of 30° C./70° C. 0 months 2.44; 12 0 months 2.44; 12 months 0 months 2.44; 12 Pimobendan months 2.44 2.41 months 2.46 40° C./75° C. 0 months 2.44; 6 0 months 2.44; 6 months 0 months 2.44; 6 months months 2.41 2.40 2.40 Degradation of 30° C./7° C. 0 months 0 months 0 months Pimobendan 1) <0.10 (K2006a); 1) <0.10 (K2006a); 1) <0.10 (K2006a); 2) <0.10 (UDCG 134 2) <0.10 (UDCG 134 BS); 2) <0.10 (UDCG 134 BS); 3) <0.10 (any 3) <0.10 (any BS); 3) <0.10 (any unspecified); unspecified); unspecified); 4) <0.10 (total); 12 4) <0.10 (total); 12 months 4) <0.10 (total); 12 months 1) <0.10; 1) <0.10; 2) <0.10; months 1) <0.10; 2) <0.10; 3) <0.10; 3) <0.10; 4) <0.10 2) <0.10; 3) <0.10; 4) <0.10 4) <0.10 40° C./75° C. 0 months 0 months 0 months 1) <0.10 (K2006a); 1) <0.10 (K2006a); 1) <0.10 (K2006a); 2) <0.10 (UDCG 134 2) <0.10 (UDCG 134 BS); 2) <0.10 (UDCG 134 BS); 3) <0.10 (any 3) <0.10 (any BS); 3) <0.10 (any unspecified); unspecified); unspecified); 4) <0.10 (total); 6 4) <0.10 (total); 6 months 4) <0.10 (total); 6 months months 1) <0.10; 1) 0.39; 2) <0.10; 3) <0.10; 1) <0.10; 2) <0.10; 2) <0.10; 3) <0.10; 4) 0.39 3) <0.10; 4) <0.10 4) <0.10 Batch No.: PB020054 Dissolution 30° C./70° C. 0 months 96 (min)-98 0 months 96 (min)-98 0 months 96 (min)-98 (max)/97 (avg); 12 (max)/97 (avg); 12 (max)/97 (avg); 12 months 93-95/94 months 90-93/91 months 93-94/94 40° C./75° C. 0 months 96 (min)-98 0 months 96 (min)-98 0 months 96 (min)-98 (max)/97 (avg); 6 (max)/97 (avg); 6 (max)/97 (avg); 6 months 90-92/91 months 90-92/91 months 91-93/92 Assay of 30° C./70° C. 0 months 2.45; 12 0 months 2.45; 12 months 0 months 2.45; 12 Pimobendan months 2.47 2.45 months 2.44 40° C./75° C. 0 months 2.45; 6 0 months; 6 months 2.39 0 months 2.45; 6 months months 2.40 2.41 Degradation of 30° C./7° C. 0 months 0 months 0 months Pimobendan 1) <0.10 (K2006a); 1) <0.10 (K2006a); 1) <0.10 (K2006a); 2) <0.10 (UDCG 134 2) <0.10 (UDCG 134 BS); 2) <0.10 (UDCG 134 BS); 3) <0.10 (any 3) <0.10 (any BS); 3) <0.10 (any unspecified); unspecified); unspecified); 4) <0.10 (total); 12 4) <0.10 (total); 12 months 4) <0.10 (total); 12 months 1) <0.10; 1) <0.10; 2) <0.10; months 1) <0.10; 2) <0.10; 3) <0.10; 3) <0.10; 4) <0.10 2) <0.10; 3) <0.10; 4) <0.10 4) <0.10 40° C./75° C. 0 months 0 months 0 months 1) <0.10 (K2006a); 1) <0.10 (K2006a); 1) <0.10 (K2006a); 2) <0.10 (UDCG 134 2) <0.10 (UDCG 134 BS); 2) <0.10 (UDCG 134 BS); 3) <0.10 (any 3) <0.10 (any BS); 3) <0.10 (any unspecified); unspecified); unspecified); 4) <0.10 (total); 6 4) <0.10 (total); 6 months 4) <0.10 (total); 6 months months 1) <0.10; 1) 0.36; 2) <0.10; 3) <0.10; 1) <0.10; 2) <0.10; 2) <0.10; 3) <0.10; 4) 0.36 3) <0.10; 4) <0.10 4) <0.10

Product: Pimobendan chewable tablets 5 mg HDPE bottle (m) PVC/PVDC (m) Aluminium blister (m) Batch No.: PB020059 Dissolution 25° C./60% 0 months 94 (min)-96 0 months 94 (min)-96 0 months 94 (min)-96 (max)/95 (avg); (max)/95 (avg); 24 (max)/95 (avg); 24 24 months 83-90/88 months 83-92/88 months 85-89/87 30° C./70° C. 0 months 94 (min)-96 0 months 94 (min)-96 0 months 94 (min)-96 (max)/95 (avg); (max)/95 (avg); 24 (max)/95 (avg); 24 24 months 83-95/89 months 82-97/88 months 83-91/87 40° C./75° C. 0 months 94 (min)-96 0 months 94 (min)-96 0 months 94 (min)-96 (max)/95 (avg); 6 (max)/95 (avg); 6 months (max)/95 (avg); 6 months 91-92/91 90-92/91 months 81-93/92 Assay of 25° C./60% 0 month 4.95; 24 0 month 4.95; 24 month 0 month 4.95; 24 month Pimobendan month 4.94 4.92 4.92 30° C./70° C. 0 month 4.95; 24 0 month 4.95; 24 month 0 month 4.95; 24 month month 4.90 4.92 4.96 40° C./75° C. 0 month 4.95; 6 0 month 4.95; 6 month 0 month 4.95; 6 month month 4.88 4.91 4.95 Degradation of 25° C./60% 0 months 1) <0.10 (K2006a); 0 months 1) <0.10 (K2006a); 0 months 1) <0.10 (K2006a); Pimobendan 2) <0.10 2) <0.10 (UD-CG 2) <0.10 (UD- (UD-CG 134 BS); 3) 134 BS); 3) <0.10 (any CG 134 BS); 3) <0.10 <0.10 (any unspecified); 4) <0.10 (any unspecified); 4) unspecified); 4) (total); 24 months 1) <0.10 (total); 24 months <0.10 (total); 24 <0.10; 2) <0.10; 3) <0.10; 1) <0.10; 2) <0.10; 3) months 1) <0.10; 2) 4) <0.10 <0.10; 4) <0.10 <0.10; 3) <0.10; 4) <0.10 30° C./7° C. 0 months 1) <0.10 (K2006a); 0 months 1) <0.10 (K2006a); 0 months 1) <0.10 (K2006a); 2) <0.10 2) <0.10 (UD-CG 2) <0.10 (UD- (UD-CG 134 BS); 3) 134 BS); 3) <0.10 (any CG 134 BS); 3) <0.10 <0.10 (any unspecified); 4) <0.10 (any unspecified); 4) unspecified); 4) (total); 24 months 1) <0.10 (total); 24 months <0.10 (total); 24 <0.10; 2) <0.10; 3) <0.10; 1) <0.10; 2) <0.10; 3) months 1) <0.10; 2) 4) <0.10 <0.10; 4) <0.10 <0.10; 3) <0.10; 4) <0.10 40° C./75° C. 0 months 1) <0.10 (K2006a); 0 months 1) <0.10 (K2006a); 0 months 1) <0.10 (K2006a); 2) <0.10 2) <0.10 (UD-CG 2) <0.10 (UD- (UD-CG 134 BS); 3) 134 BS); 3) <0.10 (any CG 134 BS); 3) <0.10 <0.10 (any unspecified); 4) <0.10 (any unspecified); 4) unspecified); 4) (total); 6 months 1) 0.23; <0.10 (total); 6 months <0.10 (total); 6 2) <0.10; 3) <0.10; 4) 1) <0.10; 2) <0.10; 3) months 1) <0.10; 2) 0.23 <0.10; 4) <0.10 <0.10; 3) <0.10; 4) <0.10 Batch No.: PB020060 Dissolution 25° C./60% 0 months 91 (min)-94 0 months 91 (min)-94 0 months 91 (min)-94 (max)/92 (avg); (max)/92 (avg); 24 (max)/92 (avg); 24 24 months 85-90/87 months 84-90/86 months 82-88/86 30° C./70° C. 0 months 91 (min)-94 0 months 91 (min)-94 0 months 91 (min)-94 (max)/92 (avg); (max)/92 (avg); 24 (max)/92 (avg); 24 24 months 85-90/87 months 82-90/87 months 86-90/88 40° C./75° C. 0 months 94 (min)-96 0 months 91 (min)-94 0 months 91 (min)-94 (max)/95 (avg); 6 (max)/92 (avg); 6 months (max)/92 (avg); 6 months 88-89/89 88-90/89 months 89-92/90 Assay of 25° C./60% 0 month 4.87; 24 0 month 4.87; 24 month 0 month 4.87; 24 month Pimobendan month 4.88 4.86 4.90 30° C./70° C. 0 month 4.87; 24 0 month 4.87; 24 month 0 month 4.84; 24 month month 4.83 4.86 4.89 40° C./75° C. 0 month 4.87; 6 0 month 4.87; 6 month 0 month 4.87; 6 month month 4.86 4.87 4.86 Degradation of 25° C./60% 0 months 1) <0.10 (K2006a); 0 months 1) <0.10 (K2006a); 0 months 1) <0.10 (K2006a); Pimobendan 2) <0.10 2) <0.10 (UD-CG 2) <0.10 (UD- (UD-CG 134 BS); 3) 134 BS); 3) <0.10 (any CG 134 BS); 3) <0.10 <0.10 (any unspecified); 4) <0.10 (any unspecified); 4) unspecified); 4) (total); 24 months 1) <0.10 (total); 24 months <0.10 (total); 24 <0.10; 2) <0.10; 3) <0.10; 1) <0.10; 2) <0.10; 3) months 1) <0.10; 2) 4) <0.10; <0.10; 4) <0.10; <0.10; 3) <0.10; 4) <0.10; 30° C./7° C. 0 months 1) <0.10 (K2006a); 0 months 1) <0.10 (K2006a); 0 months 1) <0.10 (K2006a); 2) <0.10 2) <0.10 (UD-CG 2) <0.10 (UD- (UD-CG 134 BS); 3) 134 BS); 3) <0.10 (any CG 134 BS); 3) <0.10 <0.10 (any unspecified); 4) <0.10 (any unspecified); 4) unspecified); 4) (total); 24 months 1) <0.10 (total); 24 months <0.10 (total); 24 <0.10; 2) <0.10; 3) <0.10; 1) <0.10; 2) <0.10; 3) months 1) <0.10; 2) 4) <0.10; <0.10; 4) <0.10; <0.10; 3) <0.10; 4) <0.10; 40° C./75° C. 0 months 1) <0.10 (K2006a); 0 months 1) <0.10 (K2006a); 0 months 1) <0.10 (K2006a); 2) <0.10 2) <0.10 (UD-CG 2) <0.10 (UD- (UD-CG 134 BS); 3) 134 BS); 3) <0.10 (any CG 134 BS); 3) <0.10 <0.10 (any unspecified); 4) <0.10 (any unspecified); 4) unspecified); 4) (total); 24 months 1) <0.10 (total); 6 months <0.10 (total); 6 <0.10; 2) <0.10; 3) <0.10; 1) <0.10; 2) <0.10; 3) months 1) <0.10; 2) 4) <0.10; 6 months 1) <0.10; 4) <0.10 <0.10; 3) <0.10; 4) 0.22; 2) <0.10; 3) <0.10; <0.10 4) 0.22 Batch No.: PB020061 Dissolution 25° C./60% 0 months 92 (min)-95 0 months 92 (min)-95 0 months 92 (min)-95 (max)/94 (avg); (max)/94 (avg); 24 (max)/94 (avg); 24 24 months 83-90/87 months 86-91/88 months 65-92/84 30° C./70° C. 0 months 92 (min)-95 0 months 92 (min)-95 0 months 92 (min)-95 (max)/94 (avg); (max)/94 (avg); 24 (max)/94 (avg); 24 24 months 84-88/87 months 81-87/85 months 88-91/90 40° C./75° C. 0 months 92 (min)-95 0 months 92 (min)-95 0 months 92 (min)-95 (max)/94 (avg); 6 (max)/94 (avg); 6 months (max)/94 (avg); 6 months 88-90/89 88-90/89 months 88-91/90 Assay of 25° C./60% 0 month 4.87; 24 0 month 4.87; 24 month 0 month 4.87; 24 month Pimobendan month 4.83 4.85 4.88 30° C./70° C. 0 month 4.87; 24 0 month 4.87; 24 month 0 month 4.87; 24 month month 4.82 4.80 4.90 40° C./75° C. 0 month 4.87; 6 0 month 4.87; 6 month 0 month 4.87; 6 month month 4.83 4.82 4.88 Degradation of 25° C./60% 0 months 1) <0.10 (K2006a); 0 months 1) <0.10 (K2006a); 0 months 1) <0.10 (K2006a); Pimobendan 2) <0.10 2) <0.10 (UD-CG 2) <0.10 (UD- (UD-CG 134 BS); 3) 134 BS); 3) <0.10 (any CG 134 BS); 3) <0.10 <0.10 (any unspecified); 4) <0.10 (any unspecified); 4) unspecified); 4) (total); 24 months 1) <0.10 (total); 24 months <0.10 (total); 24 <0.10; 2) <0.10; 3) <0.10; 1) <0.10; 2) <0.10; 3) months 1) <0.10; 2) 4) <0.10; <0.10; 4) <0.10 <0.10; 3) <0.10; 4) <0.10; 30° C./7° C. 0 months 1) <0.10 (K2006a); 0 months 1) <0.10 (K2006a); 0 months 1) <0.10 (K2006a); 2) <0.10 2) <0.10 (UD-CG 2) <0.10 (UD- (UD-CG 134 BS); 3) 134 BS); 3) <0.10 (any CG 134 BS); 3) <0.10 <0.10 (any unspecified); 4) <0.10 (any unspecified); 4) unspecified); 4) (total); 24 months 1) <0.10 (total); 24 months <0.10 (total); 24 <0.10; 2) <0.10; 3) <0.10; 1) <0.10; 2) <0.10; 3) months 1) <0.10; 2) 4) <0.10; <0.10; 4) <0.10; <0.10; 3) <0.10; 4) <0.10; 40° C./75° C. 0 months 1) <0.10 (K2006a); 0 months 1) <0.10 (K2006a); 0 months 1) <0.10 (K2006a); 2) <0.10 2) <0.10 (UD-CG 2) <0.10 (UD- (UD-CG 134 BS); 3) 134 BS); 3) <0.10 (any CG 134 BS); 3) <0.10 <0.10 (any unspecified); 4) <0.10 (any unspecified); 4) unspecified); 4) (total); 6 months 1) 0.22; <0.10 (total); 6 months <0.10 (total); 6 2) <0.10; 3) <0.10; 4) 1) <0.10; 2) <0.10; 3) months 1) <0.10; 2) 0.22 <0.10; 4) <0.10 <0.10; 3) <0.10; 4) <0.10 

We claim:
 1. A solid formulation comprising a homogenous dispersion of: pimobendan or a pharmaceutically acceptable salt thereof; a polyvalent acid selected from the group consisting of citric acid, acetic acid, maleic acid, tartaric acid or their anhydrides; and a flavor acceptable to small animals; wherein: the content of pimobendan in relation to polyvalent acid is 1:10 to 1:40; the content of polyvalent acid within the solid formulation is 2.5 to 10% (w/w); and the flavor is homogenously dispersed within the solid formulation.
 2. The solid formulation according to claim 1, further comprising one or more pharmaceutically acceptable carriers and/or excipients.
 3. The solid formulation according to claim 1, wherein the one or several excipients are selected from the group consisting of diluents, disintegrants, carriers, binders, flow regulators, lubricants and solvents.
 4. The solid formulation according to claim 2, wherein the binder is selected from the group consisting of polyvidone/povidone, methylcellulose, hydroxypropylmethylcellulose (HPMC), hydroxymethylcellulose, starch and gelatine.
 5. The solid formulation according to claim 2, wherein the disintegrant/carrier is selected from the group consisting of lactose, starch, cellulose, microcrystalline cellulose and methylcellulose.
 6. The solid formulation according to claim 5, wherein the lactose consists of coarse particles greater than 200 μm in size.
 7. The solid formulation according to claim 2, wherein the starch or various starches are selected from the group consisting of native starch, gelatinized starch, partly gelatinized starch, starch powder, starch granules, chemically modified starch and swellable physically modified starch.
 8. The solid formulation according to claim 2, wherein the disintegrant is selected from the group consisting of croscarmellose sodium, sodium starch glycolate, pregelatinised starch and cross-linked polyvinylpyrrolidone.
 9. The solid formulation according to claim 2, wherein the flow regulator is selected from the group consisting of silica, preferably colloidal anhydrous silica, calcium silicate, magnesium silicate and talc.
 10. The solid formulation according to claim 2, wherein the lubricant is selected from the group consisting of magnesium stearate, calcium stearate, glyceryl behenate, polyethylene glycol, stearic acid and talc.
 11. The solid formulation according to claim 2, wherein the flavor is selected from the group consisting of artificial beef flavors, artificial chicken flavors, pork liver extract, artificial meat flavor and honey flavor.
 12. The solid formulation according to claim 1, further comprising 0.5 to 20 mg of pimobendan.
 13. The solid formulation according to claim 1, wherein the weight of the whole solid formulation is in the range of 250 mg to 3000 mg.
 14. The solid formulation according to claim 1, wherein the solid formulation is a tablet or a granule.
 15. The solid formulation according to claim 1, wherein the solid formulation is a tablet and consists of 1.25 mg, 2.5 mg, 5 mg or 10 mg pimobendan, and further consists of lactose, corn starch, croscarmellose-sodium, citric acid, artificial beef flavor, polyvidone, colloidal anhydrous silica and magnesium stearate.
 16. The solid formulation according to claim 1, wherein the solid formulation is a tablet and consists of 1.25 mg, 2.5 mg, 5 mg or 10 mg pimobendan, and further consists of 35 to 50% (w/w) lactose, 25 to 50% (w/w) corn starch, 1 to 5% (w/w) croscarmellose-sodium, 2.5 to 10% (w/w) citric acid, 5 to 30% (w/w) artificial beef flavor, 1 to 5% (w/w) polyvidone, 0.1 to 1% (w/w) colloidal anhydrous silica and 0.25 to 1.5% (w/w) magnesium stearate.
 17. A tablet comprising granules compressed together, each granule comprising the solid formulation of claim
 1. 18. A solid formulation comprising a homogenous dispersion of: pimobendan or a pharmaceutically acceptable salt thereof; a polyvalent acid selected from the group consisting of citric acid, acetic acid, maleic acid, tartaric acid or their anhydrides; croscarmellose-sodium; and a flavor acceptable to small animals; wherein the flavor is homogenously dispersed within the solid formulation.
 19. A method of prevention and/or treatment of congestive heart failure in a mammal, the method comprising administering a solid formulation to the mammal, the solid formulation comprising pimobendan or a pharmaceutically acceptable salt thereof, a polyvalent acid selected from the group consisting of citric acid, acetic acid, maleic acid, tartaric acid or their anhydrides; and a flavor acceptable to small animals, wherein the flavor is homogenously dispersed within the solid formulation.
 20. A fluid-bed granulation process to form tablets comprising the solid formulation of claim 1, the process comprising: a) spraying an aqueous dispersion of pimobendan and an aqueous solution of a binder onto a solid support comprising one or several carriers and/or excipients, flavor and citric acid anhydrous; b) drying the mixture of a); c) sieving and de-agglomerating the mixture of b); d) adding a flow regulator to the mixture of c); e) adding a lubricant to the mixture of d); f) blending the mixture of e) for uniformity of granules to obtain final granules; and g) compressing the final granules of f) to tablets.
 21. The fluid-bed granulation process according to claim 19, wherein the binder of step a) is povidone, and the solid support of step a) comprises lactose, starch, flavor and citric acid anhydrous. 